A single model character on foot charges a rank and file regiment which contains a wizard and champion with the intention to kill the wizard.

The character alligns himself directly in front of the wizard which puts him in base contact, and *out* of base combat with the regiment champion. Can the champion issue a challenge to save the wizard if the has no base contact with any enemy models?

Thanks

Pg 99
'Note that in order to participate in a challenge, either to issue or meet it, a character must be in base to base contact'

Only in base to base contact, not necessarily with the other character. If the regimental champion was not in base to base with any opponent then no.

As the single character decided to engage the unit then I feel that the regimental champion could issue a challenge. As I don't have my copy of the BRB I can't tell you the page number but some where in there among the single character stuff it says that a single character is for all intents and purposes a unit, if two units engage in combat then any character involved in the combat can issue and meet the challenge.

Nope, you must be in base-to-base contact to issue a challenge. In the example given, the champion would have to sit and watch as the mage gets pummeled.

On the other hand, the mage could just refuse.

Now that would be the smart thing to do.

Well it would be stupid for the hero to challenge wouldnt it, he wanted to challenge with the champion to save the mage.